Means for expanding piston rings



Nov.6, 1923.

W. R. SCOTT MEANS FOR EXPANDING PISTON RINGS Filed Jung 6, 1922 PatentedName, 1923.

- tennisits :i on nxranmneymsron RINGS A plicant filed J'nnefi, 1922;Serial No; '566,366; f

panding Piston Rings, of which the. follow ing is'a specification. r v pv One ob ect of my invention is'to locate a spring r1ng between the baseof the groove in a piston and the split. piston ring so' as to forcethepiston ring'yieldingly against the wall of a cylinder.

A further object of the inventioniis to design the" coiled sprlng .ringso thatfit will readily accommodate itself to the movement of the pistonring in-the cylinder;

The invention relates pa-rticularly'to explosive engine pistons,

tively small and in 'which the rings must be gas tight in freely in thecylinders. 1 I V In the accompanying drawings: Fig. 1 is a side view ofthe piston of an the piston-ringof a cylinder. r 1 1 Referring to thedrawings, 1 is the piston of a gas engine in the present instance.

andlocated in gle piston ring in each groove; ln each groove,

yiel dingly' against the wall of the cylinder so as to make a fluidtightjoint between the piston and the cylinder; The "rings also center thepiston in the cylinder.

The convoluti'ons of the-spring ring are made in a particular mannersothat one'convolution will. overlap another,

clearly in Figs. 2 and 3. The convolutions are on tangential linesdrawnirom points from the center, of the pis x some distance ton; Thefulcrum of'each convolution of the springis at Eat the inner wall eitheflattened? This is due to the fact that one Whenjthc"; usual manner, thecon which are comparaorder to obtain the r 'ullpower of the explosion ofthe gases, but must yield. suflicientlyto allow the pistons to moveenlarged sectional view illusv trating a portionofthe piston andshowinghearing against the wall is the cylinder. Thepiston isgrooved' at 3;.each 'convolution to w thegrooves'a re'. the metallic split rings 4: ofthe usual type. Inthe pres ent instance, there are two grooves and asino mounted in a piston against the wall iota back of theipistonring,is a coiled. spring ring 5, which has sufiicient pressure to eiipand thepiston rings and to hold them cylinder; as shown against the ring is "at7 f'convolution' to 3. Thi'sjcon structionallows each groove andthehearing of eaoh convolution-z i' readily, and eachconvolution-acts}as an It win benoticed that theiring is lightly.

convolution overlaps another; rings are'm'ade'in the 160i, may-be.suitable manner-so as to make a complete ring.v 7

volutions are so. rigid that they willinot'f force the-piston ringsyieldingly against-the walls of acylinder."

' From practical experiments, it has been found thata ring made inaccordance with my invention will yet the j pressure will .beso slightthat it will 'notaffect the movement-of the. piston.

V hold the piston r ng yieldingly against the walls of a cylinder, r j

Whilemy inventio -is especially adapted for use in holding 1. The combaanea era" pistoniha ving a] groove. therein asplit metallic pistonring. mounted inthe grooveg'and a coiled spring 1;:

ring mounted the groove back of the pis I V the ringsoi aipis'ton yield7 V ingly against the wall of a cylinder, it may .510

the essential fea-r tonring,1the convolutions of the spring'rin g i.

laps anadjoining convolution, which allows I being so'a-rrange'd thatone convolution 'overfr '2 act as an independent 1 s rin havin a fulcrumoint anda loearij t; D -I .ingpoint q .2. A ri foru in forcing a.pistonrmgl gg I cylinder, said ring consisting of anfe'ndless spring wre, coiled to form-a 581168 of con 7 olutlonsfthe *convolutlons be ng.arranged r so that ,One} convolution overlaps another,

each convolution-having a1 fulcrum point holding a piston ring against3. The 5 com inationof piston hav mounted in the groove, andai-s'pringmema leer located in the groove-and 'encirclingthe' V Vpiston, the spring member ,havi'nga selfles f 1o o fi 7 spa-mg elements;whosetant ums are at one side of the point of contact with the ring soas to yieldingly force the ring against the Walls of a cylinder. 7

4. A spring consisting of a coiled wire, the convolutions of the springbeing soarranged that one convolution overlaps another in such mannerthateach convolution becomes a spring member adapted to yield about afulcrum point under a pressure transverse to the plane of the respectiveconvolution.

5. In combination, a pair of relatively movable members, one of saidmembers havlng a groove therein, a thlrd member movamember and saidgrooved member for cause 7 ing said third member to the remainingmember, the said means com prising a helical spring, the convolutions ofwhich are so arranged that one overlaps another, each convolutionconstituting a spring member having a fulcrum point and a bearing pointsuch as to exert a resilient force transverse to the convolutions.

WALTER R. soo-T'rf yieldingly engage plane of the respective

